SPECIES FACT SHEET
Common Name: Asano's trematodon moss
Scientific Name: Trematodon asanoi
Recent synonyms: Trematodon boasii, Trematodon semitortidens
Division: Bryophyta
Class: Bryopsida
Order: Dicranales
Family: Bruchiaceae
Taxonomic Note: Iwatsuki and Suzuki (2006) reported that Trematodon
boasii from the Pacific Northwest is identical to T. asanoi from Japan.
The name Trematodon asanoi has priority over T. boasii and replaces the
latter. Japanese Trematodon semitortidens also becomes a synonym of
Trematodon asanoi.
Technical Description: Plants erect, tiny, 2-4 mm tall. Leaves 2-4 mm
long, green or yellow-green, glossy, imbricate and flexuose but not much
contorted when dry, consisting of a short, sheathing blade tapering to a
long awl-shaped and flexuose apex. Setae yellow, 1-4 mm long, flexuose.
Capsules usually numerous, erect, reddish-brown, 0.5-1 mm long and
0.5 mm wide, with a yellowish neck of about the same length tapering to
the seta. Peristome well developed. The lid of the capsule (operculum)
has a distinct beak. Distinctive characters: (1) tiny plants with small
capsules subtended by a long, tapering neck, (2) growing on moist soil in
subalpine areas. Similar species: Other species of Trematodon are much
larger. Bruchia bolanderi looks similar and occurs in the same habitat
but (1) its capsule are beige or grayish and shaped like an inverted pear,
and (2) it lacks a peristome. Other descriptions and illustrations:
Schofield 1966: 203; Lawton 1971: 84; Noguchi 1987: 138 (as T.
semitortidens); Christy and Wagner 1996: VII-82; Norris and Shevock
2004a: 116; Norris and Shevock 2004b: 164; Iwatsuki and Suzuki 2006;
Zander 2007: 438.
Life History: Details for Trematodon asanoi are not documented. The
protonema is inconspicuous, forming buds and shoots in the usual
fashion of moss growth and development. Abundant production of spores
by Trematodon asanoi allows ample dispersal opportunities, but the
species is never abundant where it occurs and known localities are few
and widely scattered.
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Range, Distribution, and Abundance: British Columbia, California
(Norris and Shevock 2004a), Oregon, Newfoundland, Japan (Iwatsuki
and Suzuki 2006). In the Pacific Northwest, known from Vancouver
Island and the Cascade Range south to the Sierra Nevada. Trematodon
asanoi is one of a suite of species with a North Pacific distribution
(Schofield 1984).
National Forests: documented from the Willamette NF; suspected on all
forests in Oregon and Washington except the Siuslaw NF. In California,
documented from the Tahoe NF (Norris and Shevock 2004a). BLM
Districts: none documented or suspected.
Rare throughout its range but probably undercollected.
Habitat Associations: Forming loose mats on moist bare soil along the
edges of trails, streams and ponds in the subalpine zone. Soils usually
have some organic content and are irrigated by meltwater from lateseason snowbeds. Little is known about associated species. Habitats
probably include Phyllodoce empetriformis and Cassiope mertensiana
heath and Tsuga mertensiana, Abies lasiocarpa, and Abies amabilis forest
associations.
Threats: Trail construction, trail maintenance, and hiking may impact
Trematodon asanoi in areas of high visitation. Routing of trails away from
known sites would probably be adequate to protect populations. Climate
change is a serious long-term threat, and populations south of the
Canadian border may be at risk because of rising temperatures and loss
of habitat to competing vegetation.
Conservation Considerations: Revisit known localities and monitor the
status of the populations. Search for new populations on federal lands.
Protection of known sites from recreational activities, particularly alpine
hiking and rock climbing, will minimize risk to populations.
Conservation rankings: Global: G2G3; National: N2N3. British Columbia:
S1, Red List; California: SNR; Oregon: S1, List 2. Not reported from
Washington but probably present.
Preparer: John A. Christy
Date Completed: June 2007
Revised by Candace Fallon, February 2011
(Revision only adds Attachment 1, Photos)
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ATTACHMENTS:
(1)
Photos
References
Christy, J.A. & D.H. Wagner. 1996. Guide for the identification of rare,
threatened or sensitive bryophytes in the range of the northern
spotted owl, western Washington, western Oregon and northwestern
California. USDI Bureau of Land Management, Oregon-Washington
State Office, Portland. 222 pp.
Iwatsuki, Z. & T. Suzuki. 2006. A taxonomic revision of Trematodon
asanoi and its related species (Dicranaceae, Musci). Journal of the
Hattori Botanical Laboratory 99: 259-269.
Lawton, E. 1971. Moss Flora of the Pacific Northwest. Hattori Botanical
Laboratory, Nichinan, Japan. 362 pp.
Noguchi, A. 1987-1994. Illustrated Moss Flora of Japan. 5 volumes.
Hattori Botanical Laboratory. Nichinan, Japan. 1253 pp.
Norris, D.H. & J.R. Shevock. 2004a. Contributions toward a bryoflora of
California: I. A specimen-based catalogue of mosses. Madroño 51: 1131.
_______ & _______. 2004b. Contributions toward a bryoflora of California:
II. A key to the mosses. Madroño 51: 133-269.
Oregon Natural Heritage Information Center. 2007. Rare, threatened and
endangered species of Oregon. Oregon Natural Heritage Information
Center, Oregon State University. Portland. 100 pp.
http://oregonstate.edu/ornhic/2007_t&e_book.pdf
Schofield, W.B. 1966. A new species of Trematodon from western North
America. Bryologist 69: 202-204.
_______. 1984. Bryogeography of the Pacific coast of North America.
Journal of the Hattori Botanical Laboratory 55: 35-43.
Zander, R.H. 2007. Bruchiaceae. Pp. 433-439 in: Flora of North America
Editorial Committee. Flora of North America north of Mexico. Volume
27. Oxford University Press, New York. 713 pp.
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Attachment 1 – Photos
All photos by J. Harpel, under contract with the Oregon/Washington Bureau of Land
Management.
Alar and basal cells
Upper medial cells
Annulus
4
Leaf
Leaf apex
Peristome teeth (1)
5
Peristome teeth (2)
Capsule
Whole mount with sporophyte
6
Spores
Whole mount
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